Linux-2.6.12-rc2

[thirdparty/linux.git] / drivers / net / iseries_veth.c

/* File veth.c created by Kyle A. Lucke on Mon Aug  7 2000. */
/*
 * IBM eServer iSeries Virtual Ethernet Device Driver
 * Copyright (C) 2001 Kyle A. Lucke (klucke@us.ibm.com), IBM Corp.
 * Substantially cleaned up by:
 * Copyright (C) 2003 David Gibson <dwg@au1.ibm.com>, IBM Corporation.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 *
 *
 * This module implements the virtual ethernet device for iSeries LPAR
 * Linux.  It uses hypervisor message passing to implement an
 * ethernet-like network device communicating between partitions on
 * the iSeries.
 *
 * The iSeries LPAR hypervisor currently allows for up to 16 different
 * virtual ethernets.  These are all dynamically configurable on
 * OS/400 partitions, but dynamic configuration is not supported under
 * Linux yet.  An ethXX network device will be created for each
 * virtual ethernet this partition is connected to.
 *
 * - This driver is responsible for routing packets to and from other
 *   partitions.  The MAC addresses used by the virtual ethernets
 *   contains meaning and must not be modified.
 *
 * - Having 2 virtual ethernets to the same remote partition DOES NOT
 *   double the available bandwidth.  The 2 devices will share the
 *   available hypervisor bandwidth.
 *
 * - If you send a packet to your own mac address, it will just be
 *   dropped, you won't get it on the receive side.
 *
 * - Multicast is implemented by sending the frame frame to every
 *   other partition.  It is the responsibility of the receiving
 *   partition to filter the addresses desired.
 *
 * Tunable parameters:
 *
 * VETH_NUMBUFFERS: This compile time option defaults to 120.  It
 * controls how much memory Linux will allocate per remote partition
 * it is communicating with.  It can be thought of as the maximum
 * number of packets outstanding to a remote partition at a time.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/version.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <linux/ethtool.h>
#include <asm/iSeries/mf.h>
#include <asm/iSeries/iSeries_pci.h>
#include <asm/uaccess.h>

#include <asm/iSeries/HvLpConfig.h>
#include <asm/iSeries/HvTypes.h>
#include <asm/iSeries/HvLpEvent.h>
#include <asm/iommu.h>
#include <asm/vio.h>

#include "iseries_veth.h"

MODULE_AUTHOR("Kyle Lucke <klucke@us.ibm.com>");
MODULE_DESCRIPTION("iSeries Virtual ethernet driver");
MODULE_LICENSE("GPL");

#define VETH_NUMBUFFERS         (120)
#define VETH_ACKTIMEOUT         (1000000) /* microseconds */
#define VETH_MAX_MCAST          (12)

#define VETH_MAX_MTU            (9000)

#if VETH_NUMBUFFERS < 10
#define ACK_THRESHOLD           (1)
#elif VETH_NUMBUFFERS < 20
#define ACK_THRESHOLD           (4)
#elif VETH_NUMBUFFERS < 40
#define ACK_THRESHOLD           (10)
#else
#define ACK_THRESHOLD           (20)
#endif

#define VETH_STATE_SHUTDOWN     (0x0001)
#define VETH_STATE_OPEN         (0x0002)
#define VETH_STATE_RESET        (0x0004)
#define VETH_STATE_SENTMON      (0x0008)
#define VETH_STATE_SENTCAPS     (0x0010)
#define VETH_STATE_GOTCAPACK    (0x0020)
#define VETH_STATE_GOTCAPS      (0x0040)
#define VETH_STATE_SENTCAPACK   (0x0080)
#define VETH_STATE_READY        (0x0100)

struct veth_msg {
        struct veth_msg *next;
        struct VethFramesData data;
        int token;
        unsigned long in_use;
        struct sk_buff *skb;
        struct device *dev;
};

struct veth_lpar_connection {
        HvLpIndex remote_lp;
        struct work_struct statemachine_wq;
        struct veth_msg *msgs;
        int num_events;
        struct VethCapData local_caps;

        struct timer_list ack_timer;

        spinlock_t lock;
        unsigned long state;
        HvLpInstanceId src_inst;
        HvLpInstanceId dst_inst;
        struct VethLpEvent cap_event, cap_ack_event;
        u16 pending_acks[VETH_MAX_ACKS_PER_MSG];
        u32 num_pending_acks;

        int num_ack_events;
        struct VethCapData remote_caps;
        u32 ack_timeout;

        spinlock_t msg_stack_lock;
        struct veth_msg *msg_stack_head;
};

struct veth_port {
        struct device *dev;
        struct net_device_stats stats;
        u64 mac_addr;
        HvLpIndexMap lpar_map;

        spinlock_t pending_gate;
        struct sk_buff *pending_skb;
        HvLpIndexMap pending_lpmask;

        rwlock_t mcast_gate;
        int promiscuous;
        int all_mcast;
        int num_mcast;
        u64 mcast_addr[VETH_MAX_MCAST];
};

static HvLpIndex this_lp;
static struct veth_lpar_connection *veth_cnx[HVMAXARCHITECTEDLPS]; /* = 0 */
static struct net_device *veth_dev[HVMAXARCHITECTEDVIRTUALLANS]; /* = 0 */

static int veth_start_xmit(struct sk_buff *skb, struct net_device *dev);
static void veth_recycle_msg(struct veth_lpar_connection *, struct veth_msg *);
static void veth_flush_pending(struct veth_lpar_connection *cnx);
static void veth_receive(struct veth_lpar_connection *, struct VethLpEvent *);
static void veth_timed_ack(unsigned long connectionPtr);

/*
 * Utility functions
 */

#define veth_printk(prio, fmt, args...) \
        printk(prio "%s: " fmt, __FILE__, ## args)

#define veth_error(fmt, args...) \
        printk(KERN_ERR "(%s:%3.3d) ERROR: " fmt, __FILE__, __LINE__ , ## args)

static inline void veth_stack_push(struct veth_lpar_connection *cnx,
                                   struct veth_msg *msg)
{
        unsigned long flags;

        spin_lock_irqsave(&cnx->msg_stack_lock, flags);
        msg->next = cnx->msg_stack_head;
        cnx->msg_stack_head = msg;
        spin_unlock_irqrestore(&cnx->msg_stack_lock, flags);
}

static inline struct veth_msg *veth_stack_pop(struct veth_lpar_connection *cnx)
{
        unsigned long flags;
        struct veth_msg *msg;

        spin_lock_irqsave(&cnx->msg_stack_lock, flags);
        msg = cnx->msg_stack_head;
        if (msg)
                cnx->msg_stack_head = cnx->msg_stack_head->next;
        spin_unlock_irqrestore(&cnx->msg_stack_lock, flags);
        return msg;
}

static inline HvLpEvent_Rc
veth_signalevent(struct veth_lpar_connection *cnx, u16 subtype,
                 HvLpEvent_AckInd ackind, HvLpEvent_AckType acktype,
                 u64 token,
                 u64 data1, u64 data2, u64 data3, u64 data4, u64 data5)
{
        return HvCallEvent_signalLpEventFast(cnx->remote_lp,
                                             HvLpEvent_Type_VirtualLan,
                                             subtype, ackind, acktype,
                                             cnx->src_inst,
                                             cnx->dst_inst,
                                             token, data1, data2, data3,
                                             data4, data5);
}

static inline HvLpEvent_Rc veth_signaldata(struct veth_lpar_connection *cnx,
                                           u16 subtype, u64 token, void *data)
{
        u64 *p = (u64 *) data;

        return veth_signalevent(cnx, subtype, HvLpEvent_AckInd_NoAck,
                                HvLpEvent_AckType_ImmediateAck,
                                token, p[0], p[1], p[2], p[3], p[4]);
}

struct veth_allocation {
        struct completion c;
        int num;
};

static void veth_complete_allocation(void *parm, int number)
{
        struct veth_allocation *vc = (struct veth_allocation *)parm;

        vc->num = number;
        complete(&vc->c);
}

static int veth_allocate_events(HvLpIndex rlp, int number)
{
        struct veth_allocation vc = { COMPLETION_INITIALIZER(vc.c), 0 };

        mf_allocate_lp_events(rlp, HvLpEvent_Type_VirtualLan,
                            sizeof(struct VethLpEvent), number,
                            &veth_complete_allocation, &vc);
        wait_for_completion(&vc.c);

        return vc.num;
}

/*
 * LPAR connection code
 */

static inline void veth_kick_statemachine(struct veth_lpar_connection *cnx)
{
        schedule_work(&cnx->statemachine_wq);
}

static void veth_take_cap(struct veth_lpar_connection *cnx,
                          struct VethLpEvent *event)
{
        unsigned long flags;

        spin_lock_irqsave(&cnx->lock, flags);
        /* Receiving caps may mean the other end has just come up, so
         * we need to reload the instance ID of the far end */
        cnx->dst_inst =
                HvCallEvent_getTargetLpInstanceId(cnx->remote_lp,
                                                  HvLpEvent_Type_VirtualLan);

        if (cnx->state & VETH_STATE_GOTCAPS) {
                veth_error("Received a second capabilities from lpar %d\n",
                           cnx->remote_lp);
                event->base_event.xRc = HvLpEvent_Rc_BufferNotAvailable;
                HvCallEvent_ackLpEvent((struct HvLpEvent *) event);
        } else {
                memcpy(&cnx->cap_event, event, sizeof(cnx->cap_event));
                cnx->state |= VETH_STATE_GOTCAPS;
                veth_kick_statemachine(cnx);
        }
        spin_unlock_irqrestore(&cnx->lock, flags);
}

static void veth_take_cap_ack(struct veth_lpar_connection *cnx,
                              struct VethLpEvent *event)
{
        unsigned long flags;

        spin_lock_irqsave(&cnx->lock, flags);
        if (cnx->state & VETH_STATE_GOTCAPACK) {
                veth_error("Received a second capabilities ack from lpar %d\n",
                           cnx->remote_lp);
        } else {
                memcpy(&cnx->cap_ack_event, event,
                       sizeof(&cnx->cap_ack_event));
                cnx->state |= VETH_STATE_GOTCAPACK;
                veth_kick_statemachine(cnx);
        }
        spin_unlock_irqrestore(&cnx->lock, flags);
}

static void veth_take_monitor_ack(struct veth_lpar_connection *cnx,
                                  struct VethLpEvent *event)
{
        unsigned long flags;

        spin_lock_irqsave(&cnx->lock, flags);
        veth_printk(KERN_DEBUG, "Monitor ack returned for lpar %d\n",
                    cnx->remote_lp);
        cnx->state |= VETH_STATE_RESET;
        veth_kick_statemachine(cnx);
        spin_unlock_irqrestore(&cnx->lock, flags);
}

static void veth_handle_ack(struct VethLpEvent *event)
{
        HvLpIndex rlp = event->base_event.xTargetLp;
        struct veth_lpar_connection *cnx = veth_cnx[rlp];

        BUG_ON(! cnx);

        switch (event->base_event.xSubtype) {
        case VethEventTypeCap:
                veth_take_cap_ack(cnx, event);
                break;
        case VethEventTypeMonitor:
                veth_take_monitor_ack(cnx, event);
                break;
        default:
                veth_error("Unknown ack type %d from lpar %d\n",
                           event->base_event.xSubtype, rlp);
        };
}

static void veth_handle_int(struct VethLpEvent *event)
{
        HvLpIndex rlp = event->base_event.xSourceLp;
        struct veth_lpar_connection *cnx = veth_cnx[rlp];
        unsigned long flags;
        int i;

        BUG_ON(! cnx);

        switch (event->base_event.xSubtype) {
        case VethEventTypeCap:
                veth_take_cap(cnx, event);
                break;
        case VethEventTypeMonitor:
                /* do nothing... this'll hang out here til we're dead,
                 * and the hypervisor will return it for us. */
                break;
        case VethEventTypeFramesAck:
                spin_lock_irqsave(&cnx->lock, flags);
                for (i = 0; i < VETH_MAX_ACKS_PER_MSG; ++i) {
                        u16 msgnum = event->u.frames_ack_data.token[i];

                        if (msgnum < VETH_NUMBUFFERS)
                                veth_recycle_msg(cnx, cnx->msgs + msgnum);
                }
                spin_unlock_irqrestore(&cnx->lock, flags);
                veth_flush_pending(cnx);
                break;
        case VethEventTypeFrames:
                veth_receive(cnx, event);
                break;
        default:
                veth_error("Unknown interrupt type %d from lpar %d\n",
                           event->base_event.xSubtype, rlp);
        };
}

static void veth_handle_event(struct HvLpEvent *event, struct pt_regs *regs)
{
        struct VethLpEvent *veth_event = (struct VethLpEvent *)event;

        if (event->xFlags.xFunction == HvLpEvent_Function_Ack)
                veth_handle_ack(veth_event);
        else if (event->xFlags.xFunction == HvLpEvent_Function_Int)
                veth_handle_int(veth_event);
}

static int veth_process_caps(struct veth_lpar_connection *cnx)
{
        struct VethCapData *remote_caps = &cnx->remote_caps;
        int num_acks_needed;

        /* Convert timer to jiffies */
        cnx->ack_timeout = remote_caps->ack_timeout * HZ / 1000000;

        if ( (remote_caps->num_buffers == 0)
             || (remote_caps->ack_threshold > VETH_MAX_ACKS_PER_MSG)
             || (remote_caps->ack_threshold == 0)
             || (cnx->ack_timeout == 0) ) {
                veth_error("Received incompatible capabilities from lpar %d\n",
                           cnx->remote_lp);
                return HvLpEvent_Rc_InvalidSubtypeData;
        }

        num_acks_needed = (remote_caps->num_buffers
                           / remote_caps->ack_threshold) + 1;

        /* FIXME: locking on num_ack_events? */
        if (cnx->num_ack_events < num_acks_needed) {
                int num;

                num = veth_allocate_events(cnx->remote_lp,
                                           num_acks_needed-cnx->num_ack_events);
                if (num > 0)
                        cnx->num_ack_events += num;

                if (cnx->num_ack_events < num_acks_needed) {
                        veth_error("Couldn't allocate enough ack events for lpar %d\n",
                                   cnx->remote_lp);

                        return HvLpEvent_Rc_BufferNotAvailable;
                }
        }


        return HvLpEvent_Rc_Good;
}

/* FIXME: The gotos here are a bit dubious */
static void veth_statemachine(void *p)
{
        struct veth_lpar_connection *cnx = (struct veth_lpar_connection *)p;
        int rlp = cnx->remote_lp;
        int rc;

        spin_lock_irq(&cnx->lock);

 restart:
        if (cnx->state & VETH_STATE_RESET) {
                int i;

                del_timer(&cnx->ack_timer);

                if (cnx->state & VETH_STATE_OPEN)
                        HvCallEvent_closeLpEventPath(cnx->remote_lp,
                                                     HvLpEvent_Type_VirtualLan);

                /* reset ack data */
                memset(&cnx->pending_acks, 0xff, sizeof (cnx->pending_acks));
                cnx->num_pending_acks = 0;

                cnx->state &= ~(VETH_STATE_RESET | VETH_STATE_SENTMON
                                | VETH_STATE_OPEN | VETH_STATE_SENTCAPS
                                | VETH_STATE_GOTCAPACK | VETH_STATE_GOTCAPS
                                | VETH_STATE_SENTCAPACK | VETH_STATE_READY);

                /* Clean up any leftover messages */
                if (cnx->msgs)
                        for (i = 0; i < VETH_NUMBUFFERS; ++i)
                                veth_recycle_msg(cnx, cnx->msgs + i);
                spin_unlock_irq(&cnx->lock);
                veth_flush_pending(cnx);
                spin_lock_irq(&cnx->lock);
                if (cnx->state & VETH_STATE_RESET)
                        goto restart;
        }

        if (cnx->state & VETH_STATE_SHUTDOWN)
                /* It's all over, do nothing */
                goto out;

        if ( !(cnx->state & VETH_STATE_OPEN) ) {
                if (! cnx->msgs || (cnx->num_events < (2 + VETH_NUMBUFFERS)) )
                        goto cant_cope;

                HvCallEvent_openLpEventPath(rlp, HvLpEvent_Type_VirtualLan);
                cnx->src_inst =
                        HvCallEvent_getSourceLpInstanceId(rlp,
                                                          HvLpEvent_Type_VirtualLan);
                cnx->dst_inst =
                        HvCallEvent_getTargetLpInstanceId(rlp,
                                                          HvLpEvent_Type_VirtualLan);
                cnx->state |= VETH_STATE_OPEN;
        }

        if ( (cnx->state & VETH_STATE_OPEN)
             && !(cnx->state & VETH_STATE_SENTMON) ) {
                rc = veth_signalevent(cnx, VethEventTypeMonitor,
                                      HvLpEvent_AckInd_DoAck,
                                      HvLpEvent_AckType_DeferredAck,
                                      0, 0, 0, 0, 0, 0);

                if (rc == HvLpEvent_Rc_Good) {
                        cnx->state |= VETH_STATE_SENTMON;
                } else {
                        if ( (rc != HvLpEvent_Rc_PartitionDead)
                             && (rc != HvLpEvent_Rc_PathClosed) )
                                veth_error("Error sending monitor to "
                                           "lpar %d, rc=%x\n",
                                           rlp, (int) rc);

                        /* Oh well, hope we get a cap from the other
                         * end and do better when that kicks us */
                        goto out;
                }
        }

        if ( (cnx->state & VETH_STATE_OPEN)
             && !(cnx->state & VETH_STATE_SENTCAPS)) {
                u64 *rawcap = (u64 *)&cnx->local_caps;

                rc = veth_signalevent(cnx, VethEventTypeCap,
                                      HvLpEvent_AckInd_DoAck,
                                      HvLpEvent_AckType_ImmediateAck,
                                      0, rawcap[0], rawcap[1], rawcap[2],
                                      rawcap[3], rawcap[4]);

                if (rc == HvLpEvent_Rc_Good) {
                        cnx->state |= VETH_STATE_SENTCAPS;
                } else {
                        if ( (rc != HvLpEvent_Rc_PartitionDead)
                             && (rc != HvLpEvent_Rc_PathClosed) )
                                veth_error("Error sending caps to "
                                           "lpar %d, rc=%x\n",
                                           rlp, (int) rc);
                        /* Oh well, hope we get a cap from the other
                         * end and do better when that kicks us */
                        goto out;
                }
        }

        if ((cnx->state & VETH_STATE_GOTCAPS)
            && !(cnx->state & VETH_STATE_SENTCAPACK)) {
                struct VethCapData *remote_caps = &cnx->remote_caps;

                memcpy(remote_caps, &cnx->cap_event.u.caps_data,
                       sizeof(*remote_caps));

                spin_unlock_irq(&cnx->lock);
                rc = veth_process_caps(cnx);
                spin_lock_irq(&cnx->lock);

                /* We dropped the lock, so recheck for anything which
                 * might mess us up */
                if (cnx->state & (VETH_STATE_RESET|VETH_STATE_SHUTDOWN))
                        goto restart;

                cnx->cap_event.base_event.xRc = rc;
                HvCallEvent_ackLpEvent((struct HvLpEvent *)&cnx->cap_event);
                if (rc == HvLpEvent_Rc_Good)
                        cnx->state |= VETH_STATE_SENTCAPACK;
                else
                        goto cant_cope;
        }

        if ((cnx->state & VETH_STATE_GOTCAPACK)
            && (cnx->state & VETH_STATE_GOTCAPS)
            && !(cnx->state & VETH_STATE_READY)) {
                if (cnx->cap_ack_event.base_event.xRc == HvLpEvent_Rc_Good) {
                        /* Start the ACK timer */
                        cnx->ack_timer.expires = jiffies + cnx->ack_timeout;
                        add_timer(&cnx->ack_timer);
                        cnx->state |= VETH_STATE_READY;
                } else {
                        veth_printk(KERN_ERR, "Caps rejected (rc=%d) by "
                                    "lpar %d\n",
                                    cnx->cap_ack_event.base_event.xRc,
                                    rlp);
                        goto cant_cope;
                }
        }

 out:
        spin_unlock_irq(&cnx->lock);
        return;

 cant_cope:
        /* FIXME: we get here if something happens we really can't
         * cope with.  The link will never work once we get here, and
         * all we can do is not lock the rest of the system up */
        veth_error("Badness on connection to lpar %d (state=%04lx) "
                   " - shutting down\n", rlp, cnx->state);
        cnx->state |= VETH_STATE_SHUTDOWN;
        spin_unlock_irq(&cnx->lock);
}

static int veth_init_connection(u8 rlp)
{
        struct veth_lpar_connection *cnx;
        struct veth_msg *msgs;
        int i;

        if ( (rlp == this_lp)
             || ! HvLpConfig_doLpsCommunicateOnVirtualLan(this_lp, rlp) )
                return 0;

        cnx = kmalloc(sizeof(*cnx), GFP_KERNEL);
        if (! cnx)
                return -ENOMEM;
        memset(cnx, 0, sizeof(*cnx));

        cnx->remote_lp = rlp;
        spin_lock_init(&cnx->lock);
        INIT_WORK(&cnx->statemachine_wq, veth_statemachine, cnx);
        init_timer(&cnx->ack_timer);
        cnx->ack_timer.function = veth_timed_ack;
        cnx->ack_timer.data = (unsigned long) cnx;
        memset(&cnx->pending_acks, 0xff, sizeof (cnx->pending_acks));

        veth_cnx[rlp] = cnx;

        msgs = kmalloc(VETH_NUMBUFFERS * sizeof(struct veth_msg), GFP_KERNEL);
        if (! msgs) {
                veth_error("Can't allocate buffers for lpar %d\n", rlp);
                return -ENOMEM;
        }

        cnx->msgs = msgs;
        memset(msgs, 0, VETH_NUMBUFFERS * sizeof(struct veth_msg));
        spin_lock_init(&cnx->msg_stack_lock);

        for (i = 0; i < VETH_NUMBUFFERS; i++) {
                msgs[i].token = i;
                veth_stack_push(cnx, msgs + i);
        }

        cnx->num_events = veth_allocate_events(rlp, 2 + VETH_NUMBUFFERS);

        if (cnx->num_events < (2 + VETH_NUMBUFFERS)) {
                veth_error("Can't allocate events for lpar %d, only got %d\n",
                           rlp, cnx->num_events);
                return -ENOMEM;
        }

        cnx->local_caps.num_buffers = VETH_NUMBUFFERS;
        cnx->local_caps.ack_threshold = ACK_THRESHOLD;
        cnx->local_caps.ack_timeout = VETH_ACKTIMEOUT;

        return 0;
}

static void veth_stop_connection(u8 rlp)
{
        struct veth_lpar_connection *cnx = veth_cnx[rlp];

        if (! cnx)
                return;

        spin_lock_irq(&cnx->lock);
        cnx->state |= VETH_STATE_RESET | VETH_STATE_SHUTDOWN;
        veth_kick_statemachine(cnx);
        spin_unlock_irq(&cnx->lock);

        flush_scheduled_work();

        /* FIXME: not sure if this is necessary - will already have
         * been deleted by the state machine, just want to make sure
         * its not running any more */
        del_timer_sync(&cnx->ack_timer);

        if (cnx->num_events > 0)
                mf_deallocate_lp_events(cnx->remote_lp,
                                      HvLpEvent_Type_VirtualLan,
                                      cnx->num_events,
                                      NULL, NULL);
        if (cnx->num_ack_events > 0)
                mf_deallocate_lp_events(cnx->remote_lp,
                                      HvLpEvent_Type_VirtualLan,
                                      cnx->num_ack_events,
                                      NULL, NULL);
}

static void veth_destroy_connection(u8 rlp)
{
        struct veth_lpar_connection *cnx = veth_cnx[rlp];

        if (! cnx)
                return;

        kfree(cnx->msgs);
        kfree(cnx);
        veth_cnx[rlp] = NULL;
}

/*
 * net_device code
 */

static int veth_open(struct net_device *dev)
{
        struct veth_port *port = (struct veth_port *) dev->priv;

        memset(&port->stats, 0, sizeof (port->stats));
        netif_start_queue(dev);
        return 0;
}

static int veth_close(struct net_device *dev)
{
        netif_stop_queue(dev);
        return 0;
}

static struct net_device_stats *veth_get_stats(struct net_device *dev)
{
        struct veth_port *port = (struct veth_port *) dev->priv;

        return &port->stats;
}

static int veth_change_mtu(struct net_device *dev, int new_mtu)
{
        if ((new_mtu < 68) || (new_mtu > VETH_MAX_MTU))
                return -EINVAL;
        dev->mtu = new_mtu;
        return 0;
}

static void veth_set_multicast_list(struct net_device *dev)
{
        struct veth_port *port = (struct veth_port *) dev->priv;
        unsigned long flags;

        write_lock_irqsave(&port->mcast_gate, flags);

        if (dev->flags & IFF_PROMISC) { /* set promiscuous mode */
                printk(KERN_INFO "%s: Promiscuous mode enabled.\n",
                       dev->name);
                port->promiscuous = 1;
        } else if ( (dev->flags & IFF_ALLMULTI)
                    || (dev->mc_count > VETH_MAX_MCAST) ) {
                port->all_mcast = 1;
        } else {
                struct dev_mc_list *dmi = dev->mc_list;
                int i;

                /* Update table */
                port->num_mcast = 0;

                for (i = 0; i < dev->mc_count; i++) {
                        u8 *addr = dmi->dmi_addr;
                        u64 xaddr = 0;

                        if (addr[0] & 0x01) {/* multicast address? */
                                memcpy(&xaddr, addr, ETH_ALEN);
                                port->mcast_addr[port->num_mcast] = xaddr;
                                port->num_mcast++;
                        }
                        dmi = dmi->next;
                }
        }

        write_unlock_irqrestore(&port->mcast_gate, flags);
}

static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
{
        strncpy(info->driver, "veth", sizeof(info->driver) - 1);
        info->driver[sizeof(info->driver) - 1] = '\0';
        strncpy(info->version, "1.0", sizeof(info->version) - 1);
}

static int veth_get_settings(struct net_device *dev, struct ethtool_cmd *ecmd)
{
        ecmd->supported = (SUPPORTED_1000baseT_Full
                          | SUPPORTED_Autoneg | SUPPORTED_FIBRE);
        ecmd->advertising = (SUPPORTED_1000baseT_Full
                            | SUPPORTED_Autoneg | SUPPORTED_FIBRE);
        ecmd->port = PORT_FIBRE;
        ecmd->transceiver = XCVR_INTERNAL;
        ecmd->phy_address = 0;
        ecmd->speed = SPEED_1000;
        ecmd->duplex = DUPLEX_FULL;
        ecmd->autoneg = AUTONEG_ENABLE;
        ecmd->maxtxpkt = 120;
        ecmd->maxrxpkt = 120;
        return 0;
}

static u32 veth_get_link(struct net_device *dev)
{
        return 1;
}

static struct ethtool_ops ops = {
        .get_drvinfo = veth_get_drvinfo,
        .get_settings = veth_get_settings,
        .get_link = veth_get_link,
};

static void veth_tx_timeout(struct net_device *dev)
{
        struct veth_port *port = (struct veth_port *)dev->priv;
        struct net_device_stats *stats = &port->stats;
        unsigned long flags;
        int i;

        stats->tx_errors++;

        spin_lock_irqsave(&port->pending_gate, flags);

        printk(KERN_WARNING "%s: Tx timeout!  Resetting lp connections: %08x\n",
               dev->name, port->pending_lpmask);

        /* If we've timed out the queue must be stopped, which should
         * only ever happen when there is a pending packet. */
        WARN_ON(! port->pending_lpmask);

        for (i = 0; i < HVMAXARCHITECTEDLPS; i++) {
                struct veth_lpar_connection *cnx = veth_cnx[i];

                if (! (port->pending_lpmask & (1<<i)))
                        continue;

                /* If we're pending on it, we must be connected to it,
                 * so we should certainly have a structure for it. */
                BUG_ON(! cnx);

                /* Theoretically we could be kicking a connection
                 * which doesn't deserve it, but in practice if we've
                 * had a Tx timeout, the pending_lpmask will have
                 * exactly one bit set - the connection causing the
                 * problem. */
                spin_lock(&cnx->lock);
                cnx->state |= VETH_STATE_RESET;
                veth_kick_statemachine(cnx);
                spin_unlock(&cnx->lock);
        }

        spin_unlock_irqrestore(&port->pending_gate, flags);
}

static struct net_device * __init veth_probe_one(int vlan, struct device *vdev)
{
        struct net_device *dev;
        struct veth_port *port;
        int i, rc;

        dev = alloc_etherdev(sizeof (struct veth_port));
        if (! dev) {
                veth_error("Unable to allocate net_device structure!\n");
                return NULL;
        }

        port = (struct veth_port *) dev->priv;

        spin_lock_init(&port->pending_gate);
        rwlock_init(&port->mcast_gate);

        for (i = 0; i < HVMAXARCHITECTEDLPS; i++) {
                HvLpVirtualLanIndexMap map;

                if (i == this_lp)
                        continue;
                map = HvLpConfig_getVirtualLanIndexMapForLp(i);
                if (map & (0x8000 >> vlan))
                        port->lpar_map |= (1 << i);
        }
        port->dev = vdev;

        dev->dev_addr[0] = 0x02;
        dev->dev_addr[1] = 0x01;
        dev->dev_addr[2] = 0xff;
        dev->dev_addr[3] = vlan;
        dev->dev_addr[4] = 0xff;
        dev->dev_addr[5] = this_lp;

        dev->mtu = VETH_MAX_MTU;

        memcpy(&port->mac_addr, dev->dev_addr, 6);

        dev->open = veth_open;
        dev->hard_start_xmit = veth_start_xmit;
        dev->stop = veth_close;
        dev->get_stats = veth_get_stats;
        dev->change_mtu = veth_change_mtu;
        dev->set_mac_address = NULL;
        dev->set_multicast_list = veth_set_multicast_list;
        SET_ETHTOOL_OPS(dev, &ops);

        dev->watchdog_timeo = 2 * (VETH_ACKTIMEOUT * HZ / 1000000);
        dev->tx_timeout = veth_tx_timeout;

        SET_NETDEV_DEV(dev, vdev);

        rc = register_netdev(dev);
        if (rc != 0) {
                veth_printk(KERN_ERR,
                            "Failed to register ethernet device for vlan %d\n",
                            vlan);
                free_netdev(dev);
                return NULL;
        }

        veth_printk(KERN_DEBUG, "%s attached to iSeries vlan %d (lpar_map=0x%04x)\n",
                    dev->name, vlan, port->lpar_map);

        return dev;
}

/*
 * Tx path
 */

static int veth_transmit_to_one(struct sk_buff *skb, HvLpIndex rlp,
                                struct net_device *dev)
{
        struct veth_lpar_connection *cnx = veth_cnx[rlp];
        struct veth_port *port = (struct veth_port *) dev->priv;
        HvLpEvent_Rc rc;
        u32 dma_address, dma_length;
        struct veth_msg *msg = NULL;
        int err = 0;
        unsigned long flags;

        if (! cnx) {
                port->stats.tx_errors++;
                dev_kfree_skb(skb);
                return 0;
        }

        spin_lock_irqsave(&cnx->lock, flags);

        if (! cnx->state & VETH_STATE_READY)
                goto drop;

        if ((skb->len - 14) > VETH_MAX_MTU)
                goto drop;

        msg = veth_stack_pop(cnx);

        if (! msg) {
                err = 1;
                goto drop;
        }

        dma_length = skb->len;
        dma_address = dma_map_single(port->dev, skb->data,
                                     dma_length, DMA_TO_DEVICE);

        if (dma_mapping_error(dma_address))
                goto recycle_and_drop;

        /* Is it really necessary to check the length and address
         * fields of the first entry here? */
        msg->skb = skb;
        msg->dev = port->dev;
        msg->data.addr[0] = dma_address;
        msg->data.len[0] = dma_length;
        msg->data.eofmask = 1 << VETH_EOF_SHIFT;
        set_bit(0, &(msg->in_use));
        rc = veth_signaldata(cnx, VethEventTypeFrames, msg->token, &msg->data);

        if (rc != HvLpEvent_Rc_Good)
                goto recycle_and_drop;

        spin_unlock_irqrestore(&cnx->lock, flags);
        return 0;

 recycle_and_drop:
        msg->skb = NULL;
        /* need to set in use to make veth_recycle_msg in case this
         * was a mapping failure */
        set_bit(0, &msg->in_use);
        veth_recycle_msg(cnx, msg);
 drop:
        port->stats.tx_errors++;
        dev_kfree_skb(skb);
        spin_unlock_irqrestore(&cnx->lock, flags);
        return err;
}

static HvLpIndexMap veth_transmit_to_many(struct sk_buff *skb,
                                          HvLpIndexMap lpmask,
                                          struct net_device *dev)
{
        struct veth_port *port = (struct veth_port *) dev->priv;
        int i;
        int rc;

        for (i = 0; i < HVMAXARCHITECTEDLPS; i++) {
                if ((lpmask & (1 << i)) == 0)
                        continue;

                rc = veth_transmit_to_one(skb_get(skb), i, dev);
                if (! rc)
                        lpmask &= ~(1<<i);
        }

        if (! lpmask) {
                port->stats.tx_packets++;
                port->stats.tx_bytes += skb->len;
        }

        return lpmask;
}

static int veth_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        unsigned char *frame = skb->data;
        struct veth_port *port = (struct veth_port *) dev->priv;
        unsigned long flags;
        HvLpIndexMap lpmask;

        if (! (frame[0] & 0x01)) {
                /* unicast packet */
                HvLpIndex rlp = frame[5];

                if ( ! ((1 << rlp) & port->lpar_map) ) {
                        dev_kfree_skb(skb);
                        return 0;
                }

                lpmask = 1 << rlp;
        } else {
                lpmask = port->lpar_map;
        }

        spin_lock_irqsave(&port->pending_gate, flags);

        lpmask = veth_transmit_to_many(skb, lpmask, dev);

        if (! lpmask) {
                dev_kfree_skb(skb);
        } else {
                if (port->pending_skb) {
                        veth_error("%s: Tx while skb was pending!\n",
                                   dev->name);
                        dev_kfree_skb(skb);
                        spin_unlock_irqrestore(&port->pending_gate, flags);
                        return 1;
                }

                port->pending_skb = skb;
                port->pending_lpmask = lpmask;
                netif_stop_queue(dev);
        }

        spin_unlock_irqrestore(&port->pending_gate, flags);

        return 0;
}

static void veth_recycle_msg(struct veth_lpar_connection *cnx,
                             struct veth_msg *msg)
{
        u32 dma_address, dma_length;

        if (test_and_clear_bit(0, &msg->in_use)) {
                dma_address = msg->data.addr[0];
                dma_length = msg->data.len[0];

                dma_unmap_single(msg->dev, dma_address, dma_length,
                                 DMA_TO_DEVICE);

                if (msg->skb) {
                        dev_kfree_skb_any(msg->skb);
                        msg->skb = NULL;
                }

                memset(&msg->data, 0, sizeof(msg->data));
                veth_stack_push(cnx, msg);
        } else
                if (cnx->state & VETH_STATE_OPEN)
                        veth_error("Bogus frames ack from lpar %d (#%d)\n",
                                   cnx->remote_lp, msg->token);
}

static void veth_flush_pending(struct veth_lpar_connection *cnx)
{
        int i;
        for (i = 0; i < HVMAXARCHITECTEDVIRTUALLANS; i++) {
                struct net_device *dev = veth_dev[i];
                struct veth_port *port;
                unsigned long flags;

                if (! dev)
                        continue;

                port = (struct veth_port *)dev->priv;

                if (! (port->lpar_map & (1<<cnx->remote_lp)))
                        continue;

                spin_lock_irqsave(&port->pending_gate, flags);
                if (port->pending_skb) {
                        port->pending_lpmask =
                                veth_transmit_to_many(port->pending_skb,
                                                      port->pending_lpmask,
                                                      dev);
                        if (! port->pending_lpmask) {
                                dev_kfree_skb_any(port->pending_skb);
                                port->pending_skb = NULL;
                                netif_wake_queue(dev);
                        }
                }
                spin_unlock_irqrestore(&port->pending_gate, flags);
        }
}

/*
 * Rx path
 */

static inline int veth_frame_wanted(struct veth_port *port, u64 mac_addr)
{
        int wanted = 0;
        int i;
        unsigned long flags;

        if ( (mac_addr == port->mac_addr) || (mac_addr == 0xffffffffffff0000) )
                return 1;

        if (! (((char *) &mac_addr)[0] & 0x01))
                return 0;

        read_lock_irqsave(&port->mcast_gate, flags);

        if (port->promiscuous || port->all_mcast) {
                wanted = 1;
                goto out;
        }

        for (i = 0; i < port->num_mcast; ++i) {
                if (port->mcast_addr[i] == mac_addr) {
                        wanted = 1;
                        break;
                }
        }

 out:
        read_unlock_irqrestore(&port->mcast_gate, flags);

        return wanted;
}

struct dma_chunk {
        u64 addr;
        u64 size;
};

#define VETH_MAX_PAGES_PER_FRAME ( (VETH_MAX_MTU+PAGE_SIZE-2)/PAGE_SIZE + 1 )

static inline void veth_build_dma_list(struct dma_chunk *list,
                                       unsigned char *p, unsigned long length)
{
        unsigned long done;
        int i = 1;

        /* FIXME: skbs are continguous in real addresses.  Do we
         * really need to break it into PAGE_SIZE chunks, or can we do
         * it just at the granularity of iSeries real->absolute
         * mapping?  Indeed, given the way the allocator works, can we
         * count on them being absolutely contiguous? */
        list[0].addr = ISERIES_HV_ADDR(p);
        list[0].size = min(length,
                           PAGE_SIZE - ((unsigned long)p & ~PAGE_MASK));

        done = list[0].size;
        while (done < length) {
                list[i].addr = ISERIES_HV_ADDR(p + done);
                list[i].size = min(length-done, PAGE_SIZE);
                done += list[i].size;
                i++;
        }
}

static void veth_flush_acks(struct veth_lpar_connection *cnx)
{
        HvLpEvent_Rc rc;

        rc = veth_signaldata(cnx, VethEventTypeFramesAck,
                             0, &cnx->pending_acks);

        if (rc != HvLpEvent_Rc_Good)
                veth_error("Error 0x%x acking frames from lpar %d!\n",
                           (unsigned)rc, cnx->remote_lp);

        cnx->num_pending_acks = 0;
        memset(&cnx->pending_acks, 0xff, sizeof(cnx->pending_acks));
}

static void veth_receive(struct veth_lpar_connection *cnx,
                         struct VethLpEvent *event)
{
        struct VethFramesData *senddata = &event->u.frames_data;
        int startchunk = 0;
        int nchunks;
        unsigned long flags;
        HvLpDma_Rc rc;

        do {
                u16 length = 0;
                struct sk_buff *skb;
                struct dma_chunk local_list[VETH_MAX_PAGES_PER_FRAME];
                struct dma_chunk remote_list[VETH_MAX_FRAMES_PER_MSG];
                u64 dest;
                HvLpVirtualLanIndex vlan;
                struct net_device *dev;
                struct veth_port *port;

                /* FIXME: do we need this? */
                memset(local_list, 0, sizeof(local_list));
                memset(remote_list, 0, sizeof(VETH_MAX_FRAMES_PER_MSG));

                /* a 0 address marks the end of the valid entries */
                if (senddata->addr[startchunk] == 0)
                        break;

                /* make sure that we have at least 1 EOF entry in the
                 * remaining entries */
                if (! (senddata->eofmask >> (startchunk + VETH_EOF_SHIFT))) {
                        veth_error("missing EOF frag in event "
                                   "eofmask=0x%x startchunk=%d\n",
                                   (unsigned) senddata->eofmask, startchunk);
                        break;
                }

                /* build list of chunks in this frame */
                nchunks = 0;
                do {
                        remote_list[nchunks].addr =
                                (u64) senddata->addr[startchunk+nchunks] << 32;
                        remote_list[nchunks].size =
                                senddata->len[startchunk+nchunks];
                        length += remote_list[nchunks].size;
                } while (! (senddata->eofmask &
                            (1 << (VETH_EOF_SHIFT + startchunk + nchunks++))));

                /* length == total length of all chunks */
                /* nchunks == # of chunks in this frame */

                if ((length - ETH_HLEN) > VETH_MAX_MTU) {
                        veth_error("Received oversize frame from lpar %d "
                                   "(length=%d)\n", cnx->remote_lp, length);
                        continue;
                }

                skb = alloc_skb(length, GFP_ATOMIC);
                if (!skb)
                        continue;

                veth_build_dma_list(local_list, skb->data, length);

                rc = HvCallEvent_dmaBufList(HvLpEvent_Type_VirtualLan,
                                            event->base_event.xSourceLp,
                                            HvLpDma_Direction_RemoteToLocal,
                                            cnx->src_inst,
                                            cnx->dst_inst,
                                            HvLpDma_AddressType_RealAddress,
                                            HvLpDma_AddressType_TceIndex,
                                            ISERIES_HV_ADDR(&local_list),
                                            ISERIES_HV_ADDR(&remote_list),
                                            length);
                if (rc != HvLpDma_Rc_Good) {
                        dev_kfree_skb_irq(skb);
                        continue;
                }

                vlan = skb->data[9];
                dev = veth_dev[vlan];
                if (! dev)
                        /* Some earlier versions of the driver sent
                           broadcasts down all connections, even to
                           lpars that weren't on the relevant vlan.
                           So ignore packets belonging to a vlan we're
                           not on. */
                        continue;

                port = (struct veth_port *)dev->priv;
                dest = *((u64 *) skb->data) & 0xFFFFFFFFFFFF0000;

                if ((vlan > HVMAXARCHITECTEDVIRTUALLANS) || !port) {
                        dev_kfree_skb_irq(skb);
                        continue;
                }
                if (! veth_frame_wanted(port, dest)) {
                        dev_kfree_skb_irq(skb);
                        continue;
                }

                skb_put(skb, length);
                skb->dev = dev;
                skb->protocol = eth_type_trans(skb, dev);
                skb->ip_summed = CHECKSUM_NONE;
                netif_rx(skb);  /* send it up */
                port->stats.rx_packets++;
                port->stats.rx_bytes += length;
        } while (startchunk += nchunks, startchunk < VETH_MAX_FRAMES_PER_MSG);

        /* Ack it */
        spin_lock_irqsave(&cnx->lock, flags);
        BUG_ON(cnx->num_pending_acks > VETH_MAX_ACKS_PER_MSG);

        cnx->pending_acks[cnx->num_pending_acks++] =
                event->base_event.xCorrelationToken;

        if ( (cnx->num_pending_acks >= cnx->remote_caps.ack_threshold)
             || (cnx->num_pending_acks >= VETH_MAX_ACKS_PER_MSG) )
                veth_flush_acks(cnx);

        spin_unlock_irqrestore(&cnx->lock, flags);
}

static void veth_timed_ack(unsigned long ptr)
{
        struct veth_lpar_connection *cnx = (struct veth_lpar_connection *) ptr;
        unsigned long flags;

        /* Ack all the events */
        spin_lock_irqsave(&cnx->lock, flags);
        if (cnx->num_pending_acks > 0)
                veth_flush_acks(cnx);

        /* Reschedule the timer */
        cnx->ack_timer.expires = jiffies + cnx->ack_timeout;
        add_timer(&cnx->ack_timer);
        spin_unlock_irqrestore(&cnx->lock, flags);
}

static int veth_remove(struct vio_dev *vdev)
{
        int i = vdev->unit_address;
        struct net_device *dev;

        dev = veth_dev[i];
        if (dev != NULL) {
                veth_dev[i] = NULL;
                unregister_netdev(dev);
                free_netdev(dev);
        }
        return 0;
}

static int veth_probe(struct vio_dev *vdev, const struct vio_device_id *id)
{
        int i = vdev->unit_address;
        struct net_device *dev;

        dev = veth_probe_one(i, &vdev->dev);
        if (dev == NULL) {
                veth_remove(vdev);
                return 1;
        }
        veth_dev[i] = dev;

        /* Start the state machine on each connection, to commence
         * link negotiation */
        for (i = 0; i < HVMAXARCHITECTEDLPS; i++)
                if (veth_cnx[i])
                        veth_kick_statemachine(veth_cnx[i]);

        return 0;
}

/**
 * veth_device_table: Used by vio.c to match devices that we
 * support.
 */
static struct vio_device_id veth_device_table[] __devinitdata = {
        { "vlan", "" },
        { NULL, NULL }
};
MODULE_DEVICE_TABLE(vio, veth_device_table);

static struct vio_driver veth_driver = {
        .name = "iseries_veth",
        .id_table = veth_device_table,
        .probe = veth_probe,
        .remove = veth_remove
};

/*
 * Module initialization/cleanup
 */

void __exit veth_module_cleanup(void)
{
        int i;

        vio_unregister_driver(&veth_driver);

        for (i = 0; i < HVMAXARCHITECTEDLPS; ++i)
                veth_stop_connection(i);

        HvLpEvent_unregisterHandler(HvLpEvent_Type_VirtualLan);

        /* Hypervisor callbacks may have scheduled more work while we
         * were destroying connections. Now that we've disconnected from
         * the hypervisor make sure everything's finished. */
        flush_scheduled_work();

        for (i = 0; i < HVMAXARCHITECTEDLPS; ++i)
                veth_destroy_connection(i);

}
module_exit(veth_module_cleanup);

int __init veth_module_init(void)
{
        int i;
        int rc;

        this_lp = HvLpConfig_getLpIndex_outline();

        for (i = 0; i < HVMAXARCHITECTEDLPS; ++i) {
                rc = veth_init_connection(i);
                if (rc != 0) {
                        veth_module_cleanup();
                        return rc;
                }
        }

        HvLpEvent_registerHandler(HvLpEvent_Type_VirtualLan,
                                  &veth_handle_event);

        return vio_register_driver(&veth_driver);
}
module_init(veth_module_init);